<html>
<head>
<script>

function boom()
{
  var iframe = document.createElement("iframe");
  document.body.appendChild(iframe);
  iframe.setAttribute("src", 'data:application/vnd.mozilla.xul+xml,<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"><script>window.parent.document.body.style.display="inline"; window.parent.document.body.offsetWidth;</' + 'script></window>');
}
</script>
</head>

<body onload="boom();"></body>
</html>
